1. Field of the Invention
This invention relates to cationically polymerisable styryloxy resins and compositions containing such resins together with a polymerisation initiator.
2. Description of the Related Art
In U.S. Pat. No. 4,543,397 Woods et al, assigned to Loctite (Ireland) Limited there are described polyfunctional cationically polymerisable styryloxy compounds of the formula I or II ##STR2## where R.sup.1 and R.sup.2 are H, or one of R.sup.1 and R.sup.2 are H and the other is methyl; R.sup.3 and R.sup.4 are H, lower alkyl, or alkoxy if R.sup.2 is not methyl; R.sup.5 is a divalent hydrocarbon radical; G is a multivalent organic or inorganic radical free of amino, aliphatic hydroxyl, aliphatic thiol or other groups which interfere with cationic polymerisation; and n is an integer of two or more.
Example 2 thereof describes the preparation of an adduct of vinyl guaiacol and allyl glycidyl ether, followed by reaction of this adduct with a polyfunctional isocyanate resin commercially available under the Trade Mark BAYER Desmodur L-75 to form a high molecular weight resin. However due to the polyfunctional nature of Desmodur L-75, this resin would have urethane groupings in the backbone G.
U.S. Pat. No. 4,486,582 Hefner describes reaction monomers prepared by reacting
(1) an aromatic compound containing a polymerisable ethylenically unsaturated group and a group containing a hydrogen atom reactive with an NCO group PA1 (2) a compound having at least one oxyalkylene group and at least one group containing at least one hydrogen atom reactive with an NCO group, and PA1 (3) a compound having an average of more than one NCO group per molecule. PA1 R.sup.3 and R.sup.4 (which may be the same or different) are H, lower alkyl, or alkoxy if R.sup.2 is not methyl; PA1 R.sup.5 is a divalent hydrocarbon radical; G.sup.1 is the residue of an n-valent isocyanate prepolymer prepared by reaction of hydroxyl terminated hydrocarbon polymer halohydrocarbon selected from the groups consisting of a diene homopolymers and copolymers with an aromatic or aliphatic diisocyanate, said prepolymer being free of amino, aliphatic thiol, aliphatic hydroxyl or other groups which interfere with cationic polymerisation; PA1 and n is an integer of 2 or more.
However because of the oxyalkylene groups, Hefner's monomers would produce resins which would be susceptible to hydrolytic breakdown.
British Patent Specification No. 1,448,516 Kao Soap Co. Ltd. describes vinyl-terminated prepolymers formed by reacting (a) an organic polyisocyanate compound with (b) at least one equivalent of a compound having the formula ##STR3## wherein R is a group --CH.sub.2 -- or ##STR4## in which m is an integer from 1 to 4 and X is --H or --CH.sub.3. However such prepolymers are not styryloxy compounds and have limited capacity for cationic polymerisation.